Mattress with triple zone topper

ABSTRACT

A mattress comprises a base unit. A topper is supported above the base unit. The topper comprises an elongate rectangular body having a center zone joined between opposite end zones. The topper is of a select foam material of substantially uniform firmness and the center zone has a density greater than density of the end zones. A cover fabric layer surrounds the base unit and the topper.

FIELD OF THE INVENTION

This invention relates to an elongate topper or cushion in a mattress for supporting a recumbent human body and, more particularly, to a triple zone topper.

BACKGROUND OF THE INVENTION

A mattress, in its most basic form, comprises a base unit surrounded by a cover fabric layer. The base unit may be a conventional spring assembly having open coils secured internally and by upper and lower border wires. The spring assembly could alternatively include individual fabric pocketed coils and could eliminate the border wire. Another type of mattress, known as foam encased, includes a bottom foam layer. Four foam side walls are adhered to an upper surface of the bottom foam layer at its peripheral edges to provide a rectangular frame or box section. A support component, such as a spring assembly, foam, or the like, is loosely positioned in the box section. A top foam layer, pad or fiber, may be adhered to the tops of the side walls. With any of these designs, various layers of foam and/or upholstery fabrics may be included between the cover fabric layer and the base unit to provide varying degrees of comfort. Firmness of the mattress is generally determined by firmness of the base unit.

Various forms of foam cushions or pad, also known as toppers, have been integrated into mattress designs. Conventional mattress toppers may be traditional flat foam or may comprise convoluted cushions which reduces pressure points. An example of a convoluted foam cushion is shown in Nunez et al. U.S. Pat. No. 6,041,459, assigned to the assignee of the present application. The convoluted foam cushion described therein comprises an elongate rectangular body of uniform firmness and density including distinct comfort and support zones using different patterns of convolution.

The present invention is directed to further improvements in mattress design.

SUMMARY OF THE INVENTION

In accordance with the invention, there is provided a mattress including a topper having multiple zones of density and/or firmness.

There is disclosed in accordance with one aspect of the invention a mattress comprising a base unit. A topper is supported above the base unit. The topper comprises an elongate rectangular body having a center zone joined between opposite end zones. The topper is of a select foam material of substantially uniform firmness and the center zone has a density greater than density of the end zones. A cover fabric layer surrounds the base unit and the topper.

It is a feature of the invention that the topper is of polyethylene foam construction.

It is another feature of the invention that the topper has a planar bottom surface engaging the base unit and a convoluted upper surface.

It is a further feature of the invention that the convoluted upper surface has alternating peaks and valleys arranged in a checkerboard configuration.

It is yet another feature of the invention that the convoluted upper surface has a plurality of convolution zones providing different amounts of support.

It is still a further feature of the invention that the convoluted upper surface has a different convolution pattern in the center zone than in the end zones to providing different amounts of support.

It is yet a further feature of the invention that convoluted upper surface has at least five convolution zones providing different amounts of support.

It is an additional feature of the invention that the convoluted upper surface has seven convolution zones providing highest support in a central area and gradually decreasing support at longitudinal ends of the topper.

It is yet another feature of the invention that the topper has a planar bottom surface engaging the base unit and a planar upper surface having a plurality of upwardly opening slots in a grid pattern of a first size in the central zone and a second size in the end zones.

It is still another feature of the invention that the center zone has a density at least 25% greater than density of the end zones.

There is disclosed in accordance with another aspect of the invention a mattress comprising a base unit. A topper is supported above the base unit. The topper comprises an elongate rectangular body having a center zone joined between opposite end zones. The topper has a planar bottom surface engaging the base unit and a patterned upper surface. The center zone has a density greater than density of the end zones. A cover fabric layer surrounds the base unit and the topper.

Further features and advantages of the invention will be readily apparent from the specification and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, partial perspective view, with parts removed for clarity, of a mattress including a triple zone topper according to the invention;

FIG. 2 is a plan view of the topper of the mattress of FIG. 1;

FIG. 3 is a sectional view taken along a line 3-3 of FIG. 2;

FIG. 4 is a plan view of a mattress topper according to a first alternative embodiment of the invention;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 4;

FIG. 6 is a plan view of a mattress topper according to a second alternative embodiment of the invention;

FIG. 7 is a sectional view taken along the line 7-7 of FIG. 6; and

FIG. 8 is a plan view of a mattress topper according to a third alternative embodiment of the invention;

FIG. 9 is a sectional view taken along the line 9-9 of FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION

Referring initially to FIG. 1, there is illustrated a mattress 10 including a foam pad or cushion, referred to herein as a topper, 12 according to the invention. Overall, the mattress 10 is generally conventional in construction and includes a base unit 14. In the illustrated embodiment of the invention, the base unit 14 comprises a conventional spring assembly having open coils secured internally and by upper and lower border wires. The base unit 14 could alternatively include individual fabric pocketed coils and could eliminate the border wire or comprise a foam encased mattress unit. The invention is not intended to be limited to any particular construction for the base unit. A plurality of lower fiber layers 16 rest on the base unit 14. The topper 12 sits on the lower fiber layers 16. Several additional upper fiber layers 18 are disposed between the topper 12 and a cover fabric layer 20. As is apparent, the cover fabric layer 20 surrounds the entire mattress 10.

As is apparent, the topper 12 can be used in various mattress configurations. The particular configuration illustrated in FIG. 1 is but one example of such a mattress. Also, the topper 12 could be provided as a separate unit which can be selectively placed atop a mattress. Moreover, the topper 12 could also be used as an insert layer in a quilt top mattress, such as a replacement for the insert layer shown in Nunez et al. U.S. Pat. No. 5,974,609, assigned to the assignee of the present application, the specification of which is incorporated by reference herein.

The topper 12 is configured to provide comfort and support to a human body, represented at B. As is apparent, different levels of comfort and support are advantageously provided for different portions of the body B. In accordance with the invention, the topper 12 is provided with three distinct zones providing different firmness and/or density and/or support.

Referring to FIG. 2, the topper 12 has a length L and width W. The length L is typically on the order of 79″. The width W varies according to the mattress size, such as twin, double, full, queen or king size. The topper 12 includes a first end zone 22 and a second end zone 24 on opposite ends of a center zone 26. Each zone 22, 24 and 26 is made of polyurethane foam, but could be of latex foam or visco-elastic memory foam. Each zone 22, 24 and 26 is made separately and then laminated together. Particularly, the first end zone 22 and center zone 26 are laminated together at a first joint 28. Similarly, the second end zone 24 and the center zone 26 are laminated together at a second joint 30. The joints 28 and 30 may comprise butt joints, or overlapping joints, or the like, as necessary or desired. In the illustrated embodiment of the invention, each zone 22, 24 and 26 has a similar firmness with the center zone 26 being of a higher density. For example, the topper 12 may have a firmness of 10 ILD (initial load deflection). The end zones 22 and 24 may have a density of about 1.2 lbs. per cubic foot, while the center zone 26 may have a density of about 3 lbs. per cubic foot. This provides greater cushioning durability in the center zone 26.

In an illustrated embodiment of the invention, each end zone 22 and 24 may have a length of about 24″, with the center zone 26 having a length of about 31″. The topper 12 includes a planar top surface 32 and an opposite planar bottom surface 34. The topper 12 may have a thickness on the order of about 1″. The end zones 22 and 24 being of identical construction, allows the mattress 10 to be turned so that either end zone 22 or 24 can be used as the head end or the foot end. As is apparent, the relative lengths of the zones 22, 24 and 26 could be varied to provide greater or lesser amounts of enhanced cushioning durability, as is apparent. Likewise, the firmness in the end zones 22 and 24 could be different from that in the center zone 26. Likewise, the density in each zone 22, 24 and 26 could be of a different amount from that mentioned above.

Referring to FIGS. 4 and 5, a topper 112 according to a first alternative embodiment of the invention is illustrated. For simplicity, the topper 112 will be described using reference numerals 100 higher than corresponding elements in the topper 12 of FIGS. 2 and 3.

The topper 112 is made of polyurethane foam, but could be of latex foam or visco-elastic memory foam, and includes a first end zone 122 and a second end zone 124 longitudinally separated by a center zone 126. The first end zone 122 is joined to the center zone 126 at a joint 128. The second end zone 124 is joined to the center zone 126 at a joint 130. The length and width of each zone 122, 124 and 126 is similar to those discussed with respect to the topper 12 discussed above. The topper 112 includes a generally planar top surface 132 and a generally planar bottom surface 134. The topper 112 has a thickness on the order of 2¼″. The firmness is substantially similar in each zone 122, 124 and 126, while the density in the center zone 126 is substantially greater than in the end zones 122 and 124. In an illustrative example, the end zones 122 and 124 have a firmness of 21 ILD and a density of 1.2 lbs. per cubic foot. The center zone 126 has a firmness of about 23 ILD and a density of about 1.65 lbs. per cubic foot. As is apparent, other firmness and densities could be used, including those discussed above relative to the topper 12.

The top surface 132 includes surface treatment in the form of a plurality of slots 140 cut through the top surface 132 in a grid pattern. A different set of slots 142 is cut through the top surface 132 of the center zone 126, also in a grid pattern. The slots 140 and 142 are about ½″ in depth. Grid spacing of the slots 140 in the end zones 122 and 124 is about 3″. Grid spacing of the slots 142 in the center zone 126 is about 6″. This provides greater cushioning support in the center zone 126.

Referring to FIGS. 6 and 7, a topper 212 according to a second alternative embodiment of the invention is illustrated. Again, for simplicity, the topper 212 uses reference numerals similar to those with respect to the embodiments of FIGS. 2 and 3 and 4 and 5, except being in the 200 number series.

The topper 212 is made of polyurethane foam, but could be of latex foam or visco-elastic memory foam, and includes first and second end zones 222 and 224 longitudinally separated from a center zone 226 by respective joints 228 and 230. The topper 212 includes a top surface 232 and a bottom surface 234. The bottom surface 234 is planar. The topper 212 differs in that the top surface 232 comprises a surface treatment in the form of a patterned convoluted surface. The top surface 232 includes what is known as “egg crate” convolutions throughout. Particularly, the convoluted top surface 232 has alternating peaks 240 and valleys 242 arranged in a checkerboard configuration. In this embodiment, each of the zones 222, 224 and 226 include a similar pattern of convolutions throughout.

Alternatively, the mattress topper 212 could include different convolution patterns in each of the zones, 222, 224 and 226. Indeed, the convolution patterns could be the same in the end zones 222 and 224, but different in the center zone 226. Alternatively, the convolutions could be zoned independently of the three different foam zones. For example, the top surface 232 could include seven zones of convolution as shown in U.S. Pat. No. 5,974,609, incorporated by reference above.

Referring to FIGS. 8 and 9, a topper 312 according to a third alternative embodiment of the invention is illustrated. Again, for simplicity, the topper 312 uses reference numerals similar to those with respect to the previous embodiments, except being in the 300 number series.

The principal difference between the topper 212 and the topper 312 is that a top surface 332 includes seven different zones of convolution. The convolutions are formed by alternating peaks 340 and valleys 342. The peaks 340 and valleys 342 are arranged in rows, with adjacent rows being staggered to form a checkerboard pattern, as is apparent. The topper 312 can be manufactured using conventional processes for convoluted foam cushions. In the illustrated embodiment of the invention, the peaks 340 have flat top surfaces. In an illustrative embodiment of the invention, the topper 312 has a height of about 2″ measured from the planar bottom surface 334 to the top of the peaks 340. The topper 312 has a base thickness of about 1½″ measured from the planar bottom surface 334 to the base of the valleys 342. The peaks 340 and valleys 342 are generally rectangular in shape, albeit having rounded edges, as is well known. The top surface 332 includes seven zones of convolution numbered 351, 352, 353, 354, 355, 356 and 357. The outermost zones 351 and 357 are similar. The next innermost zones 352 and 356 are similar. The next innermost zones 353 and 355 are similar. In the zones 351 and 357, the peaks and valleys have a lateral dimension of about 1″. In the zones 352 and 356, the peaks and valleys have a longitudinal dimension of about 2″. In the zones 353 and 355, the peaks and valleys have a longitudinal dimension of about 3″. Innermost zone 354 has peaks and valleys with a longitudinal dimension of about 5″ in length. As such, the center most convolution zone 354 provides the greatest amount of support, with support gradually decreasing moving longitudinally from the center convolution zone 354 to either end most convolution zone 351 or 357. As is apparent, the convolution zones do not and need not correspond to the three foam zones.

The topper 312 could alternatively be provided with a different number of convolution zones such as, for example, three zones or five zones. The borders of the convolution zones need not match up with the borders of the foam zones.

The invention is not limited to a particular type of surface treatment. Also, the surface treatment could be applied to the bottom surface. The surface treatment could be, for example, contoured, such as body contouring.

Each topper described herein can be constructed of polyurethane foam or of latex. Also, it could be formed of a visco-elastic memory foam.

Thus, in accordance with the invention, there is provided a triple zone mattress topper providing greater durability and support in a center zone compared to end zone. 

1. A mattress comprising: a base unit; a topper supported above the base unit, the topper comprising an elongate rectangular body having a center zone joined between opposite end zones, the topper being of a select foam material of substantially uniform firmness and the center zone having a density greater than density of the end zones; and a cover fabric layer surrounding the base unit and the topper.
 2. The mattress of claim 1 wherein the topper is of polyethylene foam construction.
 3. The mattress of claim 1 wherein the topper has a planar bottom surface engaging the base unit and a convoluted upper surface.
 4. The mattress of claim 3 wherein the convoluted upper surface has alternating peaks and valleys arranged in a checkerboard configuration.
 5. The mattress of claim 3 wherein the convoluted upper surface has a plurality of convolution zones providing different amounts of support.
 6. The mattress of claim 3 wherein the convoluted upper surface has a different convolution pattern in the center zone than in the end zones to providing different amounts of support.
 7. The mattress of claim 3 wherein the convoluted upper surface has at least five convolution zones providing different amounts of support.
 8. The mattress of claim 7 wherein the convoluted upper surface has seven convolution zones providing highest support in a central area and gradually decreasing support at longitudinal ends of the topper.
 9. The mattress of claim 1 wherein the topper has a planar bottom surface engaging the base unit and a planar upper surface having a plurality of upwardly opening slots in a grid pattern of a first size in the central zone and a second size in the end zones.
 10. The mattress of claim 1 wherein the center zone has a density at least 25% greater than density of the end zones.
 11. A mattress comprising: a base unit; a topper supported above the base unit, the topper comprising an elongate rectangular body having a center zone joined between opposite end zones, the topper having a planar bottom surface engaging the base unit and a patterned upper surface, the center zone having a density greater than density of the end zones; and a cover fabric layer surrounding the base unit and the topper.
 12. The mattress of claim 11 wherein the topper is of polyethylene foam construction.
 13. The mattress of claim 11 wherein the topper is of elastic memory foam construction.
 14. The mattress of claim 11 wherein the upper surface is convoluted having alternating peaks and valleys arranged in a checkerboard configuration.
 15. The mattress of claim 11 wherein the upper surface is convoluted having a plurality of convolution zones providing different amounts of support.
 16. The mattress of claim 11 wherein the upper surface is convoluted having a different convolution pattern in the center zone than in the end zones to providing different amounts of support.
 17. The mattress of claim 11 wherein the upper surface is convoluted having at least five convolution zones providing different amounts of support.
 18. The mattress of claim 17 wherein the convoluted upper surface has seven convolution zones providing highest support in a central area and gradually decreasing support at longitudinal ends of the topper.
 19. The mattress of claim 11 wherein the patterned upper surface has a plurality of upwardly opening slots in a grid pattern of a first size in the central zone and a second size in the end zones.
 20. The mattress of claim 11 wherein the center zone has a density at least 25% greater than density of the end zones. 